Americans don't like Congress. This much we know. But a new survey shows a historic gap between how voters feel about Congress overall and how they feel about their own representatives heading into the midterm elections.

When pollsters ask voters about Congress, they typically gauge sentiment in two ways: how voters rate Congress in general, and how they feel about their specific members of Congress. The latter measure invariably surpasses the former — voters tend to dislike Congress as a whole, but generally harbor more favorable opinions about their specific representatives.

New numbers from Gallup show a 31-point gap between those who think most members deserve re-election and those who think their own representative does. Just 19% of registered voters think most members of Congress should be re-elected, while 50% of respondents think their specific member deserves another term in office.

This disparity is the "the widest such gap in a midterm year in Gallup's history," and may indicate that 2014 will be a year with higher Congressional turnover than usual.

Voters' views this year about most members of Congress have descended to the lowest levels ever seen, while their views of the advisability of re-electing their member, although historically low, are no lower than they have been in previous midterm election years.

The gap, therefore, is due to dislike of Congress as a whole: "The percentage of American voters who believe most members of Congress deserve re-election is at an all-time low." Even though voters may like their own representatives, dislike for the institution as a whole is higher than ever.

Gallup sums it up like this:

It appears Americans are evaluating representatives on how they are doing their job and representing the district, while evaluating the institution as a whole on its collective inability to get much done.